"I was 10 years old when my parents got divorced," he tells PEOPLE. "It's a pretty common story in America, and it's a pretty tough time for kids, especially if they're still at home in the middle of growing up."

Acknowledging that "seeing his family fall apart was a traumatic moment" in his life, the "All of Me" singer says he's thankful he had his teachers to fall back on.

"It was important to have teachers and counselors at school who could give emotional support," says Legend, 35, who is working with Turnaround for Children in the hopes of improving in-need public schools through teacher training. "All of these people took extra time to show me that they cared and were going to hold me accountable."

Over the years, the Grammy winner has visited several schools in New York that have received training from the organization. "It's exciting to know that they see a real difference … in test scores and morale," he says. "[The students] were really happy and felt like there was much more support for them."

Legend himself was homeschooled for several years, then went on to finish high school in the public education system before graduating from the University of Pennsylvania with an English degree.

"One of the most determining factors of your success in life is whether you stick with something," he says. "Finishing school is a manifestation of that."

For more of our interview with Legend, pick up the latest issue of PEOPLE, on newsstands Friday